面向嵌入式驱动软件开发的设备仿真技术研究

分析了传统嵌入式驱动软件开发模式的不足，提出了一种基于仿真设备的软硬件协同开发模式。详细论述了设备仿真技术的具体设计与实现，结合应用实例证明了该技术能较有效地缩短嵌入式驱动软件开发周期。

A New Device Simulation Method for Shortening Development Period of Embedded System

Existing device simulation methods for embedded driver development, to our best knowledge, do not pay enough attention to computer hardware simulation, thus making development period of embedded system unnecessarily long. Proprietary I/O devices are often involved in many computer application systems, especially in embedded systems. In such scenarios, developers have to develop drivers for these devices to utilize them under some embedded operating system. Traditionally, development of device driver can be undertaken only after hardware design finishes. However, with the increasing competition among corporations, shorter time to market is important for a successful product. To shorten the development cycle of device driver, this paper proposes using a simulation device as the target of driver's operation. Previous related works (Refs.1 and 2) on device simulation mainly focus on how to support development of application level software and are not suitable or not complete for software with extensive device accesses, especially device drivers. This paper presents a device simulation mechanism based on an abstraction model of I/O devices. We abstract a device to include only IRQ, registers, and its action logic. We believe that, if we can simulate the three elements, we can say we have simulated the device successfully. We use a software module, essentially a driver module residing in kernel address space, called device simulator, to simulate the three basic elements of real hardware. The three elements are simulated by a kernel memory buffer, a variable, and a user provided periodically invoked switch case routine respectively. Besides that, a simulation framework for device driver development is discussed. The framework is composed of a simulation driver auto generator and a simulation control panel. With this framework, developers can generate device simulators easily and develop effectively real device driver without the need of hardware existence. Because the running of application software relies on the underlying device driver, it is natural that this framework also supports the development of the entire system without requiring hardware involvement. Our simulation mechanism and the framework have been implemented on Windows and Linux platform and good results are obtained.